Vintage Cars: OIL LEAK FROM REAR MAIN SEAL, corvair owners, oil leaks

Question
Jeff,I have owned and driven my 57 Thunderbird for the past 30 years and have had to replace the rear main seal many many times with both the rope and Poly (rubber?) seal with NO LASTING results. Engine has been taken out and inspected for any "sand holes " in block and all looks well but seal? keeps spotting my driveway. What am I missing??

Answer
Keep in mind I'm no mechanic, but I do own a '65 Corvair, so I'm certainly familiar with oil leaks.  They say it isn't a true Corvair if it doesn't mark its territory with oil!  Seriously, you said you've had to replace the rear main seal many times, and I think that's your issue.  Two things: lack of usage and new technology.  I think so many of the problems we face with our old cars is due to lack of use.  If you don't drive it often, then seals dry out and start to leak.  Corvair owners have discovered Viton seals, which seem to last forever.  Do they make such a thing in a rear main seal for a Ford V8?  Definitely worth looking into.  If Viton isn't available, then I'd try to drive the car more often.  If you think I'm off base or would like to follow up on this, please don't hesitate to respond.